For the wonderful price of 11$ + shipping, I recently acquired:

Ram Doubler 8 on CD "Optimized for OS 8, Apple's Newest and fastest OS!" ~1998

Ram Doubler 1.6.2 on Floppy "You'll be rid of Out of Memory messages forever!" ~1994 *

Ram Doubler 1.5.2 on Floppy "Compatible with Macintosh AND Power Macintosh" ~1994

*It also has a folder labeled "Old", but the readme won't open in it. It says it is in use by another application. All of these also came with their original docs and are ...presumably... licensed.